/* Compute the intersection of src_1 and src_2 and write the result to
* dst. It is allowed for dst to be equal to src_1. We assume that dst is a
* valid container. */
void array_run_container_intersection(const array_container_t *src_1,
const run_container_t *src_2,
array_container_t *dst) {
if (dst->capacity < src_1->cardinality)
array_container_grow(dst, src_1->cardinality, INT32_MAX, false);
if (src_2->n_runs == 0) {
return;
}
int32_t rlepos = 0;
int32_t arraypos = 0;
rle16_t rle = src_2->runs[rlepos];
int32_t newcard = 0;
while (arraypos < src_1->cardinality) {
const uint16_t arrayval = src_1->array[arraypos];
while (rle.value + rle.length <
arrayval) { // this will frequently be false
++rlepos;
if (rlepos == src_2->n_runs) {
dst->cardinality = newcard;
return; // we are done
}
rle = src_2->runs[rlepos];
}
if (rle.value > arrayval) {
arraypos = advanceUntil(src_1->array, arraypos, src_1->cardinality,
rle.value);
} else {
dst->array[newcard] = arrayval;
newcard++;
arraypos++;
}
}
dst->cardinality = newcard;
}
/* Compute the intersection of src_1 and src_2 and write the result to
* dst. */
void array_bitset_container_intersection(const array_container_t *src_1,
const bitset_container_t *src_2,
array_container_t *dst) {
if (dst->capacity < src_1->cardinality)
array_container_grow(dst, src_1->cardinality, INT32_MAX, false);
const int32_t origcard = src_1->cardinality;
dst->cardinality = 0;
for (int i = 0; i < origcard; ++i) {
// could probably be vectorized
uint16_t key = src_1->array[i];
// next bit could be branchless
if (bitset_container_contains(src_2, key)) {
dst->array[dst->cardinality++] = key;
}
}
}
/* Compute the andnot of src_1 and src_2 and write the result to
* dst, a valid array container that could be the same as dst.*/
void array_bitset_container_andnot(const array_container_t *src_1,
const bitset_container_t *src_2,
array_container_t *dst) {
// follows Java implementation as of June 2016
if (dst->capacity < src_1->cardinality)
array_container_grow(dst, src_1->cardinality, INT32_MAX, false);
int32_t newcard = 0;
const int32_t origcard = src_1->cardinality;
for (int i = 0; i < origcard; ++i) {
uint16_t key = src_1->array[i];
if (!bitset_container_contains(src_2, key)) {
dst->array[newcard++] = key;
}
}
dst->cardinality = newcard;
}
